In loading and unloading of trucks and/or trailers parked at a loading dock, it has been found that unless the truck or trailer is effectively secured in place, serious accidents and mishaps to both personnel and equipment can occur by reason of the vehicle accidentally or prematurely moving away from the dock.
Various ways to cope with this problem have heretofore been employed, such as, for example, wedging of blocks in front of the vehicle wheels; utilizing taut cable or chain to positively secure the vehicle to the front of the dock; or utilizing manually, electrically and/or hydraulically actuated locking devices mounted on the front of the dock or on the roadway adjacent the dock. Such approaches to cope with the aforementioned problem, however, are beset with one or more of the following shortcomings: (a) the blocks are susceptible to being lost, vandalized, or damaged; (b) the effectiveness of the blocks is seriously impaired when the roadway supporting the vehicle is subjected to ice, snow, rain, oil or grease spills; (c) the effectiveness of the blocks, chains, or cables is dependent primarily upon the conscientious effort exerted by the driver of the vehicle and not upon the dock personnel responsible for loading or unloading of the vehicle; (d) the locking device is of costly and complex construction and is highly susceptible to malfunction due to changes in weather or being struck by the vehicle when the latter is being maneuvered into a parked position; and (e) the locking device is awkward and difficult to operate and/or install.